MOTOTRBO GPS in a nutshell

Radios with model names ending with a 1 (e.g. DP3601 or DM4401) have an integrated GPS receiver. This receiver is purely a reporting tool (i.e. the radio user cannot see where they are like on a traditional GPS unit). MOTOTRBO radios uses a protocol called LRRP (Location Request Response Protocol) to send GPS updates to a predefined Radio ID (i.e. destination address). LRRP uses triggers to schedule GPS updates: these include GPIO event; delta time; delta distance or immediate.

GPS updates are processed by a location server (effectively a standard PC with a tracking application on it). The operator (person) sends a location request to a radio via the tracking application installed on the PC. The server is connected to a Control Station, which is used to send the request. This location request contains information about the triggers: for example, send GPS data every ten minutes or every 1 kilometer, whichever happens first (this is chosen by the operator via the location application).

The Control Station can be any MOTOTRBO radio - mobile or portable. The radio is connected to the server via a standard USB cable. This radio would be programmed to monitor the radio channel or system.

[Edit 10.09.13] Note that as of system release 2.2, control stations are not required and certain Application Partner products are able to access the radio network directly via the repeaters. This uses the NAI feature (Network Application Interface).

The radio stores this location request and when one of the triggers have been reached, the radio sends a GPS packet (takes less than 600ms). The GPS is sent as UDP/IP data over the air, to the predefined Radio ID. The radio which receives this packet forwards this to the PC, which displays the radio location on a map. There are different ways to handle the GPS update, in terms of channels and coordination.

Another MOTOTRBO feature which works hand-in-hand with GPS is ARS (Automatic Registration Service). This causes the radio to send a registration packet every time the user switches on or (optionaly) changes site. ARS is also supported in non-GPS models.

The map and location request management, is part of one of many possible applications from several possible Motorola Application Partners.

More details on how GPS is handled in MOTOTRBO can be found in the MOTOTRBO System Planner. More information on which Motorola Application Partners produce GPS tracking applications can be found in the Application Partner Catalogue. Both of these documents are available to Channel Partners, for download from Motorola Online. The Application Partner catalogue is available for download on my Blog or on Motorola's website.

If you dont have access to Motorola Online, you can request a copy of the latest MOTOTRBO System Planner from your Motorola Supplier. A summarised version of the MOTOTRBO Application Partner Catalogue is available on the web at http://bit.ly/RzwoDd.